The post-cast strip should be reserved according to the design requirements, and the concrete should be poured at the time specified in the design, with a general width of 800 mm-1000 mm and an interval of 30-40m, which runs through the cross section of the whole structure and divides the structure into several independent sections, but the indefinite straight line passes through an opening to avoid the overlapping of 100% steel bars.

Generally, the rear belt passes through the cross section of beam and plate or the intersection of vertical and horizontal walls or the connecting beam at the entrance of the door. The grid connection length of the steel bar between the slab and the wall is 45d, and the main bar of the beam can be continuously opened to maintain a certain connection.

Post-cast strip is a temporary construction joint set at the corresponding position of foundation slab, wall and beam according to the requirements of design or construction specification in order to prevent harmful cracks that may be caused by uneven shrinkage or uneven settlement of cast-in-place reinforced concrete structure during construction.

The post-cast strip will temporarily divide the structure into several parts, and after the internal contraction of the components, the construction joint concrete will be poured after a period of time to connect the structure into a whole area.

Extended data:

Function:

1, workability

The most important performance of concrete mixture. The properties of the mixture, such as consistency, fluidity, plasticity, anti-delamination, segregation and bleeding, and easy plastering, are comprehensively shown. There are many methods and indicators to measure and express the workability of mixture. The slump (mm) measured by truncated cone slump cone and Weibull time (sec) measured by Weibull instrument are mainly used as the main indicators of consistency in China.

2. Strength

The most important mechanical properties of concrete after hardening refer to the ability of concrete to resist pressure (such as compression, tension, bending and shearing). Water-cement ratio, variety and dosage of cement, variety and dosage of aggregate, and mixing, molding and curing all directly affect the strength of concrete.

The strength grades of concrete according to the standard compressive strength are called labels, which are divided into C 10, C 15, C20, C25, C30, C35, C40, C45, C50, C55, C60, C65, C70, C75, C80, C85, C90.

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